Implantable microelectrode arrays are useful tools in various applications, including providing brain stimulation in the treatment of neurological and psychiatric disorders, as well as providing neuroscientists with the ability to research neurophysiology. Long-term use of implantable microelectrode arrays would expand these applications. However, conventional implantable microelectrodes have limited useful lifetimes when implanted in body tissue, because tissue encapsulation forms around the electrode site as a foreign body response, which often increases noise and electrical impedance between the electrode and tissue and decreases signal amplitude. Long-term use of implantable microelectrodes in the brain requires low electrical noise and high mechanical stability. Furthermore, interfacial boundary layers that form between each material in an implanted microelectrode should be clean, have similar surface energies, and possess adequate adhesion strength to withstand water, oxygen, ions, and other aspects of the surrounding environment. Polymers are an attractive choice of material because of their diverse bulk properties and alterable surface chemistry, but are inherently porous to water, oxygen, and salts, which decreases the long-term usefulness of a polymer implantable microelectrode. Thus, there is a need in the implantable electronics field to create an improved method to manufacture implantable electronics. This invention provides such an improved method for manufacturing an implantable electronic device.